Patents such as U.S. Pat. Nos. 575,004 579,960, 632,796, 841,201, 570,994, 1,109,646, 1,404,182 and 1,596,503 show devices for providing a canceling facility in association with a mailbox which in most instances operates as the letter or postcard is being inserted in the mailbox. U.S. Pat. No. 575,004 to McLean on a combined stamp canceling, postmarking and recording mailbox shows a device which postmarks a letter and cancels a stamp as a letter is inserted in the mailbox. The McLean device includes rollers between which the letter moves. Anderson, U.S. Pat. No. 1,404,182 shows a die roller, a felt roller and spring loaded idler support roller which are activated by rack teeth on the mailbox door.
These prior art mailbox stamp cancelling devices have not gained universal acceptance since most are subject to vandalism and jamming or are so complex that they cannot be deployed economically in the numerous existing mailboxes. The prior art cancelers also are subject to operational errors since in most instances, it is required that the mailer insert the letter or postcard in the mailbox with a preferred orientation to assure that the stamp is cancelled thereby.